SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5ab447b5922f0d5a70e654d2b39fd719799863f1995c99e56cc973935ae9cb8' 
  AND token = 'xy0YUZt/jvtu2hLVnBumwrwdG02U3ggfrPW+q5skMM0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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