SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1261ed48cb1547d33d476d5e667371d621ad5ba8db32e69ad8dff4f57192f1a' 
  AND token = 'GHkIH/qLcruSLByRFLddmmY8TjNjiOKl+IVyaThfnMc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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