SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5226b6dbac67079287f4e38539d580d93c38bad0c83adb7c9fbbf8560d95d521' 
  AND token = 'PQAuBzQzElRCMVNq6DABVKnTJAuO8O6IX2P6Wv5FIGc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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