SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cb9055d5c3ac68b1ccbcdb8bf9a31532977e8cfe2a781096d7655826e9bccd55' 
  AND token = 'eXoTLMlFcQunWEyD9QVWHCXyE/4IRaUDbkOgVMMlPsM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}