SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9b239fc7e31c6ec554088773eb303cad9562dbe15ab457551eaf3b378621ff17' 
  AND token = '+skUBRpGcFbqb8PrQ5e9i/3WVMr1tZgNkHDwHETuOY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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