SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '085b16bd61c74f538baf076767b2849051269186eba2324c0be4ab942a7239a4' 
  AND token = '5ARQadcnvo6Tmhs/EoBDl1G+UzJEb+InzP9CZlrYn3Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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