SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb877b94175b175526ef214f42154ed655f05b181c915472db090ad14b33b0d4' 
  AND token = 'JEefQD47oRaUKYYx+p+LKN3O41bKco56YDwEw7U7PMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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