SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5648c9df285ada9b2ffc64193958b9e0e87d5ad5bcb582e37fae48f5964ca678' 
  AND token = 'pgHyWH3cRBoM2SmQ67fWacRVeTDGoqRMWsEgOHfwOuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}