SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2d327c31058f074385e88dc94cdda1d644f5a97a83273e66dd668794576cb0c' 
  AND token = 'Jfqvu/oBo9+fPtrmkqOMy5YXH1Qmj36nRd8R6dcXMc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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