SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf3c3e67d14310d2019c72680507beae270c98f0fef9a34c4c2662f38dae9eac' 
  AND token = '8ZwDNmf252YEGIMBLcalzoPUW5ICjtRZRSacy1grg8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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