SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c9062fc6bdc584b7310d60d737cd7620b9c061ebbfaad7988314d977e989f8e' 
  AND token = 'nwU84VPEhEFVvbCxbLho9VO+HQGQnIFOhHtYyHEef7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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