SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '265fe0861349dfdabfde8ef36189cda4381e9541ce3c170a67f44cd1bacd8821' 
  AND token = 'qo7RW40hiAf7EGNTJbH/EXoj6ecRKrZaP7Rj+yWSOgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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