SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bd5e03fb20957a8caafeb57bc049e9f0451a0144bfa66541020f11d8e13c894' 
  AND token = 'XPhP2XGbOjWd7Ihq6eswaO96U4FHLDBkyCxkMlaVQeE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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