SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0bf0a12909c691c47aed204bd8e8747626be1b29e0adc69cdee338e6ddd1cdf' 
  AND token = 'rwIGC+GL16k/l4s9yFHqdcgz7RcoBd54EAW3ui3w8Hs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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