SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd075d9fb96b13fa30facb95fbb9656dc860073a458671a2cb529cc769f6362a7' 
  AND token = '3gmgZvwrXy2UI+KrrsrqBPJSJZ73KYQmenoJcvh2qIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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