SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f103569851ac23bd3fde6678a7d27265e5dde479be8f3668514b6eac0ed31127' 
  AND token = 'ulI0v5M3Hxvw46vUM4CzqYCBegTbNnzb+oFS9s6AgBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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