SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12199683b286585a7513dad183eed640f9b2cc0e2349ee824377b150f6d29134' 
  AND token = 'jPum7Fm/vBkFlTq2CJ/VSBdJWN2vywZqR1Q1HtOji6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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