SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4d1acb80bb7387a19743b4cdd6c3f99b14b7b9ef133f0274760b505d153a59e' 
  AND token = '6iX+kz/fqA0gPsVytWloDLejp4wL1FbSTv7OYuSYC2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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