SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcc895ec1e9cd362d5879743e9786ef55fd914e834c4fe05f8a556be9e347a67' 
  AND token = 'mmsrmJP+PTxnMlYxefqEeSYgQXWwwAVbysKYeiiLAcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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