SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b41df943cebfcebcb3aab2705bdf15910ed5e377d31ab0eb96a51852201eef24' 
  AND token = '8A518jlshOG6Z4gfcIfR5ZalWtDsgiAGnN8IDiPAzKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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