SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0983c729af925af3b15d6a79f44ecb474aba246d28f9bb69331043f02364dbe8' 
  AND token = 'uOsM70liABGEKJP7sU/Xb+PuROez0r4u0J+SFlEzcaE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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