SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca561b97ea42555cba96bd6c64434eff0afb28f9b4f589126e4fc9a82c233e10' 
  AND token = 'rETFO4NgahaqDYW8K1yPzScRqcYIQ0mQfuWOIv2tFhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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