SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a858390ccc09431f82beb0528155c6941ab4d30d4a2e8e89615e11e8911d1ef' 
  AND token = 'tonjMwWnF4c1bNYfKKWmYblbVHvY7vH2n6juKupaoMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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