SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd1e73a94d60844fdcd2956f586ac96fc0c9740b9ffa2ebc2de5a6bea0cb2cf2' 
  AND token = 'vTAyuwsx/+aA75ows2YMovR40UtSHWcaKCAbXTDrKIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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