SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3e364374c72e876d0302eb985e7d5d691d8303181bfe629704b07e4a883aba5' 
  AND token = 'pQG0vmSr8DBpHZAFzPLvZhwVnUhYf3ANTGp1CRfBd6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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