SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '333bffc3325f1ad93091d04f86335207bc43c79c421a1c58c19c325f2d62f950' 
  AND token = 'aKwcPPpvJkPPhjvbnpwjriLRimryMB7AhTlNzl6qbfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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