SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04941eb22b730dd5572b31aa6629007dd0772969e8c42ed4843a275947163943' 
  AND token = 'srBGw3qAgBp08nwTfK2BcpcxanGDh1+V+fxFOuWPjNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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