SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ddef8325ce6f4db892c2492eb0fdc8e0fd9f531d963083f9a111990411e4bf1' 
  AND token = 'ZlOvjez8GKrDM1upfuNPAyPx2W4nnARebmKgnuHxObQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}