SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5febffb9a8f1f84a12468f912405825fa6ae39f2e8b70a0fe7839b92a51af546' 
  AND token = 'yvyKwhZhdbOdxUr2/X0ximzfWeQYLPMDyayshEwkPsc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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