SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '016239aa20578bf52fd54c87c3f05177f5d329364b6a687a9b1f35d60cc4378d' 
  AND token = 'mE+BRW51CqVbwFSkdDBI6NgdN83bGi6T2SX9olW0al8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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