SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24b6728493c38195120553aba19bfb6542c843448f76a5ac951ec90426c05864' 
  AND token = 'oI7DHTE4IhF+Bv09mfh/DeHnFFaPUqL1ypeNwz9VEdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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