SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aada2c19a0bc589fde5054ac6cbcd32ec684da657d689d847ba2168072c4e576' 
  AND token = '8nrsKMcQttd78fa4fA6/uY+HixB7oDdRvheo28I9LgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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