SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85e3f0d5408a95675e1ab31fcac2dc43195c7a84d51b409d39d873882a3867b2' 
  AND token = '5sasvzas0LwqZKFRyD6i2DeKE1lhkKOBNGXoq8w4J+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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