SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f23a387162865e6c4d49db826a3e9eb9f799f8bb5c9b70d9bc8cccf17292b31e' 
  AND token = 'b3ePb2dUhKk3kPXJjURsrsigw1Bq0uR3THhxkcUt5NA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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