SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15e7425ba531cd6f753466ff251c099d9928dce4c85b072f78ba3f807365f335' 
  AND token = 'gV8dAi/Me16jvMjbSKWgeV2zmonmvQZPl2BAMAB/Bng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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