SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc745114f6b8bb02cecd4b0203af8fa4f70f788bd721aa96ac9170a593e541cd' 
  AND token = 'wSD9cSXnVs0P4NkKhxfakUp1BnG7dkWp2Hl5s6Hlv8A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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