SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e0bfeffd35d18aa84a685fa2982c24ab05337999341f1d2e5aab47ae805977c' 
  AND token = 'kygNnvFprjimaqrgKfm6vahQ1DP9Lm1ahrrvCtHxxDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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