SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac0d2c0452410876750eb50ee4585faa0b8b55bbadc752fc4011ee7b349dd0da' 
  AND token = 'je5JGzYNJbxAEsajFkNfRVOOq+1mWwAJpN6hJbol4Q8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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