SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f430dd51c27261f9a0bfcb0f6bf600ea60e9c8c6d36499f6a65745771b8f20c' 
  AND token = 'uqMKj+4f23FtxPpKumfvjZ+etOwOfTVAqmOb+oauVFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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