Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '814f29000e7e0232931fae5d50947e2fd2e753b1ba0e54f8576ce822bf5b98a0' 
  AND token = 'BQRwKxkwJhFe8HKUFaikfTsgWmpjOfEoebKwC71n1r4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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