SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '123efdccad9d96880a7f34dcb96e79cee45171fdd42a0848ad1c59f263bc739f' 
  AND token = 'iCgp5ooWP1VEhb2cbQHDk6M4Mr0/QaamzqabNM0nMuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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