SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fed62ca49e11e64eb40c5620466fd3a1facad6e0adbabd25355dca0ed9f173bd' 
  AND token = 'ukKLJ7nHquiTQUPIJxYMoLoevqFV7hxyhxMaHNxSHco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}