SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a90d184bc750ec5791c79ea74bd1c070103cbd6b79757716d72d83c18d81dd19' 
  AND token = 'CiGnugb3m4EayfLRCfkerWXOdvCvyVIWgvDmpqZ7mG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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