SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4546fc9481702a6bee259606611b92474af5f7b4bbdd5a79870fc7bbd70ee280' 
  AND token = 'q8YKkBsobAECYTZ52Z5WZKfP9GWP06azzqvaMYrvUVY=' 
  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"
    }
  }
}