SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1645a7b7876d75e301b04e82b2472259c604236be4dd280d186bc45a00213646' 
  AND token = 'AVdNmoesLSvXDIMVKs0eF8Hl6mwWhl4Zf7sZ0040rfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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