SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67fda85271da44a06551234924354ce0b89cbd814abdad501999fcc800e247a9' 
  AND token = 'n8ot42oBSUDAFdJXn8MlHTaWiEnmp14WFq+atOTweMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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