SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '352637e3f2cfb8adfe79e822be831afca3d27c145e11e0c6ceae1587bcc27b87' 
  AND token = 'M9wkfy9MHIxBqiP0pFMPnn5Nkvt124/5u8ymFZGPQK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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