SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd033cfef168db428a08c80c341f33c459d880a6a650443d166f03ee75ebaf4c8' 
  AND token = 'bcZgCP4gSc8kxNBP8E0XWU58+aTBhtAqWBK3YrQTMis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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