SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e7fe36e0ce221ede8f3307fe947ecefad73ae9357a000ace5cddac1e12f5c07' 
  AND token = 'inJ5SWThfG35qoUb+T3HtOeCefyQn1LcrOyGwi5s818=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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