SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66f9ceff8db340ba8f40964d843231086bd353125b9cb9027069fc5f2407f40c' 
  AND token = 'kU7bIxSCFQiwb4Iag41dl16szbk1+G1GTjRl2ndXKk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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