SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04879591f5db74e07b9589b692136245be2999b17090b4c1ba42ddbda4b5f8f4' 
  AND token = 'BbOV4mt1B3aY5umQwSLMM2i5EdxbAIg8VdjPgCYoaiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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