SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4314f74c1da0195b0375f0d97e844cfc41be6ad4ceb5664bd2dbefa4130d795d' 
  AND token = 'OpGTQaCmmubWyxt1hOAiIKoBskSl7YrK66iMEPYwpmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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