SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66e2279bf5f7761fddcf4085322ed099e02005f3eb0eecc8f97796941505915b' 
  AND token = 'pFZpdPApmPWNy4MMV151RO5Ext8HGQ04eHUsr3Ubqn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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