SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f2f8bd71a5f90d773e2c8c7a39be34175f81ce68af597267cd4dc910c4e5ada' 
  AND token = 'ppRotAGW26zfXfdzCqOcuvXClbxCJKuSVY4asjcWgRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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