SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0d23682b7c24600fec0b284912171a5e9ee77cbd0934b7222daeeea8f6666a0' 
  AND token = 'ZPLjJPudnnmmnb+4DOSXZWmqOa+Bv0i4xuvOEIi92iQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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