SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ba9054257d822a37daf112e500be91569bf5e4f2e436ebfd29d947649801ed4' 
  AND token = 'o9WZsYDR0dD9BvCaPhNyZ+N2xCE6N/Bmno6EupEJbj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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