SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cdaafd5b0ef3d97024d845b0953dcf6f27b623d30a12108ee39b9d50c4409a3' 
  AND token = 'w+SzP89/Ogww4QusI8aK5n87nyZGqTxSBezIeMeML0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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