SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9c5a4015eea6fce5ad018a04583066870c70292f4609b7f5c32676e136a6c3f6' 
  AND token = 'ZXtGWONep2zMFuzVKHiHFO9XAt3dVGquMILOiX4cH2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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