SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b22f3351ac78f19ed72410c5304a1d5059d1fc04cc93a80f33a426d82d205dd6' 
  AND token = 'bYIqm9zXQO+VdBwLbHKOGjCfnTga1Kgc2DfZyxFiS2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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