SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4486be35d0558d39017a514cda0f7f8d6c5b3a5a630e7f315eaacf434fb36bbf' 
  AND token = 'YU7xEA3OIiO+rwCMJ76DtsMHcifjWTGxyRiSriYjCjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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