SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a973356723f3d97d550e7e85ae3517c590aa1f62c6bcae74758aa3a1143038b' 
  AND token = 'Lq5Gw/pqQmDmI/YXmx8QAtbJvuY/v2H9dcNzjwTYxhQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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