SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'efc7702b40abe7e7b4db9e6569dd500f5947931761c58ad21c43828dd5638414' 
  AND token = 'Nci/66xOL+9mlH5bD1AYA2U1hXVRee/cpvhiX4D2Q7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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